Chita Rivera, who plays the prostitute Nickie in the movie, originated the role of Velma Kelly in the original Broadway production of "Chicago" in 1975. In the 1990s, she played the role of Roxie Hart in the London production of the smash revival of Chicago.

The director, Rob Marshall, wanted Catherine Zeta-Jones to wear her natural long hair in the movie, (why I have no idea seeing as long hair was out then, and the bob was extremely common) but she insisted on the short bob. She explained to People magazine that she didn't want her hair to fall in front of her face and give people a reason to doubt that she did all her own dancing.

Madonna, Goldie Hawn, Kathy Bates, Rosie O'Donnel, Nicole Kidman, Gwyneth Paltrow, Cameron Diaz, and Britney Spears were all considered for roles. (That's a scary combo..)

John Travolta, Kevin Spacey, and Hugh Jackman were all considered for the role of Billy Flynn. (Personally, I like the one we got!)

Originally Gwen Stafani was asked to play the character Mona, but was too busy with touring at the time. So Mya was then approached with the part and took it. We couldn't have asked for a better Mona! ;)

Chicago is the fourth film that John Travolta has turned down and which Richard Gere has accepted, following American Gigolo (1980), Days of Heaven (1978), and An Officer and a Gentleman (1982).

Catherine Zeta-Jones added Velma's pose for the photographers in the Cell Block Tango. Richard Gere added the reciting to himself of Roxie's lines during the trial.

Richard Gere took tap dance lessons for three months. His tap dance scene was shot in half a day.

Throughout the movie Billy Flynn calls John C. Reily's character (Amos) "Andy" -which is a reference to the radio show "Amos 'n' Andy".

Deirdre Goodwin (June), Denise Faye (Annie), Taye Diggs (bandleader), and Sebastian LaCause (Al Lipschitz) were all cast members of the "Chicago" revival.

The song "Class" was apparently filmed but not used because it could not fit into the "show-within-Roxie's-mind" concept. Currently it is included as an appendix on the DVD.

The Hunyak's dialogue translated is as follows:

"What am I doing here? Why do they say, the famous Police, that I held down my husband and with an axe cut off his head? It isn't true! My hands are white (meaning: I am innocent). I don't know why they have told Uncle Sam that I did this. I tried to explain to them but they will not understand...